1. Field of the Invention
The invention relates to an electromagnetic switching apparatus having a base whose bottom is fixed to a wall and in a cavity of which is disposed a control electromagnet with mobile armature adapted for actuating, through detachable coupling means, a transmission piece connected to a mobile contact of a single cut-out switch situated in an insulating case provided with opposite input and output terminals, this case being removably associated with a surface for fixing the base opposite the bottom.
Such an apparatus, which may be used in all power distribution systems may, depending on the embodiment of its controlled switch or switches, provide either repeated opening and closing of a circuit feeding a load, or else, and in association with devices sensitive to overloads or a current fault, provide automatic opening of the circuit for protecting the lines and/or the load.
2. Description of the Prior Art
A known apparatus, such as the one which is illustrated by the French Pat. No. 2 257 141 in the name of the applicant, and whose general construction recalls the one which is mentioned above, has solely the contactor function.
Within a general arrangement different from this latter, a circuit breaker apparatus is also known which is illustrated, for example, by the French Pat. No. 2 573 571 of the applicant, where a mobile piece of a single-cut out switch may be actuated either by a remote controlled electromagnet housed in a base, or else be opened by repulsion forces developed on the appearance of short circuit currents.
Finally, from the French Pat. No. 2 570 872 of the applicant and U.S. Pat. No. 4,644,308 of the assignor, a switch apparatus is known in which one or more control modules of different kinds may be associated with a base containing a controlled switch device, so as to confer on this switch one of the functions of supplying or protecting a load, which were mentioned above.
It is known that it is not easy to confer on the same switch a construction such that it is capable of responding with the same efficiency to operating conditions as different as those intended to provide either repeated opening and closing of the circuit and its load, or ensuring the protection thereof.
Under first working conditions of the contactor type, this switch must be able to maintain its mechanical and electric properties at a relatively high temperature which is developed by the frequent passage of currents going from the nominal current to 10 times this current Whereas, in working conditions of the circuit breaker type in which this switch will be rarely in action, the energy to be dissipated in the case during cut off of the very high currents will be much greater; in both cases, conditions of good residual insulation after numerous specific operations will have to be guaranteed in comparable ways.
Moreover, it is desirable to give the user the opportunity of rapidly changing a switch which has become defective without it being necessary to disconnect all the conductors which are connected thereto, an operation which is made difficult in an apparatus such as that defined in the French Pat. No. 2 257 141.
The present invention consequently provides an electric switching apparatus whose construction corresponds to that which is mentioned in the introduction and in which measures will be taken so that switch modules having different functions may be associated rapidly and without error with a standard base and separated therefrom without disconnection of the corresponding conductors, while providing each complete apparatus with an insulation of good quality.